Nicaise de Keyser (1813-87) studied at the Academy in Antwerp with Mathieu Ignace Van Brée. He exhibited altarpieces influenced by Rubens at the Salons of 1834 and 1835. After success in 1836 with his huge canvas, Battle of the Gold Spurs, he received commissions from royalty and from prominent families at home and abroad. In 1848 he became a member of the Koninklijke Academy in Brussels, and in 1855 he was appointed director of the Academy in Antwerp. His large history paintings and his genre scenes deal with Romantic subjects, but the execution is often cold and academic. Although celebrated during his lifetime, his art was soon forgotten after his death.

Leopold succeeded his father as King of the Belgians in 1865. His father described him in 1864 as ‘more selfish and fantastical than ever’. He had an unhappy marriage and his only son died in 1869. His dissolute private life caused estrangement between him and his English relatives. Leopold was founder and sole owner of the Congo Free State (present day Democratic Republic of the Congo), which he exploited as an immense rubber plantation, harvested by enslaved people controlled with a barbarity which shocked even at the time (and was eventually exposed in the Casement Report of 1905).  

This portrait is one of a pair depicting the Duke and his Duchess (RCIN 405103 & 405108) and one of three works by this artist in the collection (see RCIN 405151). The sitter is shown full-length, wearing the Belgian uniform with red facings, and the ribbon of the Order of Leopold over his right shoulder; his helmet rests on a chair beside him.